(USA TODAY) -- The Port Authority, which operates the bridge at the heart of a New
Jersey scandal, has told a U.S. Senate committee inquiry that there is
"zero evidence" that any legitimate traffic study was being carried out
at the time the access lanes were closed.

The statement,
given to Sen. Jay Rockefeller, D-W.Va., comes as two New Jersey
committees were preparing to subpoena key aides to Gov. Chris Christie
in their investigation of whether his top advisers orchestrated or
covered up lane closures near the George Washington Bridge for political
purposes.

The agency told the senator that it "shares your
concern regarding the aberrational events that occurred at the George
Washington Bridge last September, which are not in any way
representative of the manner in which business is conducted at the Port
Authority."

The Port Authority statement came in response to an
inquiry from Rockefeller, who is chairman of the Commerce, Science and
Transportation Committee, which may open its own investigation.

"The
Port Authority's response provides zero evidence that the purpose of
these closures was to conduct a legitimate traffic study," Rockefeller said in a statement.

As
the bridge scandal unfolded in December, aides to Christie attempted to
explain the abrupt closures of key access lanes to the bridge in Fort
Lee, N.J., as part of a traffic study.

As recently as last week,
when Christie fired deputy chief of staff Bridget Anne Kelly for
allegedly lying to him about the incident, he continued to hold out the
prospects that a study might have been involved, at least in part.

Rockefeller
had asked the Port Authority a series of questions in December
following testimony before a New Jersey legislative committee looking
into the lane closings.

The agency responded by letter Wednesday, the deadline set by Rockefeller for a reply.

"The
letter explains the careful planning and communication that should
happen before interstate bridge lanes are closed for a traffic study or
any other non-emergency purpose," the senator said.

He said in a
statement that the Port Authority officials who ordered the four-day
closures beginning Sept. 9 "did not follow their agency's own
procedures."

In its letter to Rockefeller, the Port Authority said that lane closures were never carried out unannounced.

"Any
traffic study that would require lane closures would require advanced
communications to other transportation operators, local municipalities,
and the traveling public," the agency said..

Two Christie appointees to the authority, David Wildstein and Bill Baroni, have resigned in the wake of the scandal.

On
Thursday, the New Jersey Assembly created a special investigative
committee to look into the scandal and was expected to issue subpoenas
soon. In addition, a New Jersey Senate committee is also investigating the case.

The
unannounced lane closures, which lasted four days, created huge traffic
jams in Fort Lee, which is located at the base of the bridge, and
raised speculation that it was retribution against the town's Democratic
mayor for declining to endorse Christie for re-election in November.

As
a sign of increasing pressure, Christie announced Thursday that he has
hired an outside law firm, including a former federal prosecutor, to
head up an internal review of the case and to deal with the legislative
inquiries and a probe by the U.S. attorney's office, the Asbury Park Press reports.

Christie said in a statement that hiring a law firm "will bring an outside, third-party perspective to the situation."

A
member of the law firm, Randy Mastro, is a former assistant U.S.
attorney in the southern district of New York who specialized in
organized crime and racketeering cases.

In yet another development, Christie's former campaign manager, Bill Stepien, has hired an attorney,The (Bergen) Record reports.

The
special committee created by the New Jersey Assembly has appointed its
own former federal prosecutor, Reid Schar, to serve as special counsel.
Schar successfully prosecuted former Illinois governor Rod Blagojevich,
who is serving a 14-year sentence for corruption.

"I am
confident these talented legislators have the backgrounds, temperaments
and experience to conduct this inquiry in a bipartisan, professional and
responsible manner," newly sworn-in Assembly Speaker Vincent Prieto, a
Democrat, said after appointing the special committee.

Among those
who could receive subpoenas are Port Authority Chairman David Samson, a
Christie adviser; Christie aide Regina Egea, who is slated to become
Christie's new chief of staff; and Michael Drewniak, the governor's
chief spokesman.

The Senate committee that is running its own investigation will also subpoena documents and witnesses.

"I'm
not going to rule anybody out," said Senate Majority Leader Loretta
Weinberg, who will chair the investigative committee in the upper house.
"There are many other questions here."

Christie, who said he had
no prior knowledge of the lane closures, said last week that he would
cooperate "with all appropriate inquiries to ensure this breach of trust
does not happen again."

The role of Kelly, Christie's
former deputy chief of staff, emerged in e-mails subpoenaed by a New
Jersey transportation committee and released last week.

In
one e-mail exchange between Kelly and Wildstein about two weeks before
the lane closures, Kelly wrote: "Time for some traffic problems in Fort
Lee."

To which Wildstein replied: "Got it."

Christie, in
announcing Kelly's dismissal, said he did not quiz her about why she
sent the directive, saying he did not want to be accused of interfering
with a witness in the case.